* 1. Basic constructor validation
     * --------------------------------------------------------------------- */
    @Test
    void constructorAcceptsNonNullObject() {
        // Arrange : create a dummy address
        InetAddress dummy = mock(InetAddress.class);
        // Act
        UniAddress ua = new UniAddress(dummy);
        // Assert

        // Arrange
        when(negotiationResponse.isDFSSupported()).thenReturn(false);

        // Act
        boolean result = negotiationResponse.isDFSSupported();

        // Assert
        assertFalse(result);
        verify(negotiationResponse).isDFSSupported();
    }

    @Test
    @DisplayName("Test setupRequest method")
    void testSetupRequest() {
        // Arrange

    @DisplayName("unwrap, domain, anonymous/guest flags happy paths")
    void unwrap_and_flags_happy(boolean[] flags) {
        boolean anonymous = flags[0];
        boolean guest = flags[1];

        // Arrange
        Subject subject = new Subject();
        TestCredentials creds = new TestCredentials("DOMAIN", anonymous, guest, subject, false);

        // Act & Assert

            // Arrange & Act
            SmbFile file = new SmbFile(url, mockCifsContext);

            // Assert
            assertNotNull(file);
            assertEquals(mockCifsContext, file.getContext());
        }

        @Test
        void testConstructorWithStringURL() throws MalformedURLException {
            // Arrange & Act

    @Mock
    private SmbTreeHandleInternal handle;

    @Test
    @DisplayName("release(): verifies it is invoked exactly once")
    void release_invokedOnce() throws Exception {
        // Arrange: no setup needed; we verify interaction only

        // Act: call release
        handle.release();

        // Assert: verify one invocation and no more
        verify(handle, times(1)).release();

        assertEquals("", transWaitNamedPipe.name);
    }

    @Test
    @DisplayName("writeSetupWireFormat should write correct bytes")
    void testWriteSetupWireFormat() {
        // Arrange
        transWaitNamedPipe = new TransWaitNamedPipe(mockConfig, testPipeName);
        byte[] dst = new byte[10];
        int dstIndex = 0;

        // Act

        // Arrange
        byte[] dst = new byte[100];
        int dstIndex = 0;

        // Act
        int result = response.writeParametersWireFormat(dst, dstIndex);

        // Assert
        assertEquals(0, result);
    }

    @Test
    @DisplayName("writeDataWireFormat should return 0")
    void testWriteDataWireFormat() {
        // Arrange
        byte[] dst = new byte[100];

        testData = new byte[] { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08 };
    }

    @Test
    @DisplayName("Test sign method with valid parameters")
    void testSignWithValidParameters() {
        // Arrange
        int offset = 0;
        int length = testData.length;

        // Act
        signingDigest.sign(testData, offset, length, request, response);

        // Assert

        // Assert
        assertEquals(-1, actual);
    }

    @Test
    @DisplayName("Structure: DOS_ERROR_CODES is non-null with [code,status] pairs")
    void dosErrorCodesStructureIsValid() {
        // Arrange & Act
        int[][] table = DosError.DOS_ERROR_CODES;

        // Assert
        assertNotNull(table, "DOS_ERROR_CODES must not be null");
        assertTrue(table.length > 0, "DOS_ERROR_CODES must not be empty");

    @DisplayName("renew() behaviors across implementations")
    void renewBehaviorsAcrossImplementations(String label, Supplier<SmbRenewableCredentials> supplier, boolean expectSame,
            boolean expectNew) {
        // Arrange: create an implementation instance
        SmbRenewableCredentials impl = supplier.get();

        // Act: call renew
        CredentialsInternal renewed = impl.renew();